The present invention relates generally to a dispenser, and in particular to a dispenser for dispensing metered quantities of liquid from a container.
There are many instances where it is desired to dispense from a container, for instance a bottle or the like, metered quantities of liquid. By way of example, which will hereafter be used to explain the invention but should not be considered limiting, reference is made to the dispensing of alcoholic beverages from bottles. There, it is often desirable and, in the case of commercial establishments, important that the alcoholic beverage be dispensed from a bottle in uniform metered amounts. To aid in dispensing such uniform amounts, it is already known to provide dispensing devices which are mounted on the bottle (or other container) so that, when the bottle is tilted, liquid from the bottle flows into the dispensing device to be dispensed from the same in a metered quantity.
In particular, the prior art knows a device having a housing provided with a dispensing tube which is located within the chamber formed in the housing but has an outer outlet end, and which is surrounded with spacing within the chamber by an outer tube. The liquid which enters the chamber from the bottle rises in the clearance between the outer tube and the dispensing tube until it reaches the upper open end of the dispensing tube and flows into the latter. During this rising of the liquid, a corresponding quantity of air is drawn via an air tube communicating with the chamber and with the interior of the bottle, into the latter due to the suction which develops in the bottle as liquid is poured out of it. After the liquid has risen to the upper open end of the dispensing tube, it pours into the latter and this interrupts the further entry of air via the air tube into the bottle. The outflow of liquid through the dispensing tube continues until the liquid level in the chamber has reached the lower end of the outer tube, so that now air can again be drawn from the chamber through the clearance into the air tube, which causes the flow of liquid to be interrupted. If at this time the bottle is not righted, but instead continues to be maintained at a pouring angle, then air will again enter into the bottle via the air tube and the chamber of the housing of the dispensing device will again fill with liquid which becomes dispensed.
This prior art arrangement has the advantage that the amount of liquid being discharged is automatically metered and that no levers or other mechanical devices such as valves or the like are required to effect such metering. Such devices are susceptible to malfunction, for instance if the liquid being dispensed happens to be viscous or tacky, as might be the case if a liqueur is dispensed, because this leads to sticking of the mechanical devices and their malfunction. However, the aforementioned prior-art arrangement has a disadvantage which makes it less than completely satisfactory. Specifically, the prior-art device can be used only with dispensing tubes of small internal cross section. The reason for this is that it is of primary importance that the amount of liquid entering the dispensing tube should completely fill the cross section of the latter, if an accurately metered quantity of liquid is to be dispensed. However, such complete filling of the cross section of the dispensing tube is possible in the prior-art device only if the cross section is small, because otherwise the liquid entering the dispensing tube tends to cling to the inner surface of the tube and leaves the remaining portion of the tube cross section empty, which then interferes with proper metering of the dispensed liquid.